No current usage.
(†Saypo Limestone Member of Madison Limestone (MT-local) considered abandoned.)

Geologic age:

Early Mississippian (Tournaisian; Kinderhookian)

Type section, locality, area and/or origin of name:

Type locality: on south side of upper part of Pentagon Mountain, in SW/4 sec. 14, T. 25 N., R. 12 W., [Pentagon Mountain 7.5-min quadrangle, Flathead Co.], northwestern MT. Named from Saypo quadrangle (scale 1:125,000), over much of which it is well exposed (Deiss, 1933).